package com.hmdp.utils;

import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWorker {

    /*
    * 初试时间戳
    * */
    private static final long BEGIN_TIMESTAMP = 1640995200L;

    /*
    * 序列号长度
    * */
    private static final int COUNT_BITS = 32;

    private StringRedisTemplate stringRedisTemplate;
    public RedisIdWorker(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }

    public long nextId(String keyPrefix) {
        //1.生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowSecond - BEGIN_TIMESTAMP;
        //2.生成序列号
        //获取当前日期
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        //获取序列号,自增长(在redis中写的生成了多少id)
        Long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);
        //3.拼接返回
        return timestamp << COUNT_BITS | count;
    }


    /*
    * 生成初试时间戳
    * */
   /* public static void main(String[] args) {
        LocalDateTime time = LocalDateTime.of(2022, 1, 1, 0, 0, 0);
        long second = time.toEpochSecond(ZoneOffset.UTC);
        System.out.println(second);
    }*/
}
